The major objective of this research is to determine the quaternary structure of ribosomes by studying altered forms of the ribosomal subunits. Physical analyses of unfolded subunits, protein -deficient subunits and ribosomal fragments will be made by means of sedimentation velocity, sedimentation equilibrium, viscometry and small-angle x-ray scattering experiments. These analyses will provide a determination of the sedimentation coefficients, molecular weights, intrinsic viscosities, radii of gyration and the shape of the particles studied. This information will aid considerably in understanding the physical structure of the ribosomal subunits. In turn, this information is of critical importance in trying to understand the functions of the ribosome in protein synthesis.